The field of art to which this invention pertains to fluid catalyst regeneration. It relates to the rejuvenation of particulated-solid, fluidizable catalyst which has been contaminated by the deposition thereupon of coke. The present invention will be most useful in a process for regenerating coke-contaminated fluid cracking catalyst, but it should find use in any process in which coke is burned from a solid, particulated, fluidizable catalyst.